sched: allow the immediate migration of cache-cold tasks

allow the immediate migration of cache-cold tasks.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sched.c b/kernel/sched.c
index 3b27c3a553aa3a0b20a7e78248d6795d60ad6ff0..750612751a7f1266c7d564e81ea846d75e1e4f0b 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1016,6 +1016,11 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
        if (p->sched_class != &fair_sched_class)
                return 0;
 
+       if (sysctl_sched_migration_cost == -1)
+               return 1;
+       if (sysctl_sched_migration_cost == 0)
+               return 0;
+
        delta = now - p->se.exec_start;
 
        return delta < (s64)sysctl_sched_migration_cost;
@@ -2189,7 +2194,8 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
         * 2) too many balance attempts have failed.
         */
 
-       if (sd->nr_balance_failed > sd->cache_nice_tries) {
+       if (!task_hot(p, rq->clock, sd) ||
+                       sd->nr_balance_failed > sd->cache_nice_tries) {
 #ifdef CONFIG_SCHEDSTATS
                if (task_hot(p, rq->clock, sd)) {
                        schedstat_inc(sd, lb_hot_gained[idle]);